Hi, I've managed through imaging Lingo to create an alpha
channel and place it in/on to a Bitmap. What I want to do now is
combine two Alpha's from two different Bitmaps and place it in a
thrid bitmap.

You can use imageObject.extractAlpha() to get the alpha
channels of your
2 images, copyPixels() to combine them and setAlpha() to add
the
resulting grayScale image object as an alpha channel - just
be aware
that setAlpha() will fail if the alpha channel's dimensions
don't match
the image's dimensions

I'm not quite there yet with this problem. I've extracted two
Alpha's from to different bitmaps and the only way I've managed to
combine both alpha's together is by repeating through each alpha
pixel by pixel to see if the pixel is black and if it is drawing it
into another bitmap. Once it's finished I then use setAlpha.

Even though it works it just takes a bit of time to loop
through all the pixels and I might be using his technique on more
than two bitmaps with alpha's. Is there a neat way i can do this
using copypixel?

let's say you now have alphaImg1 and alphaImg2... try
copyImages with the #ink parameter... the values for the different
inks can be found in the help... in my example below I'm going to
try using 39 - Darkest ink.